1. Technical Field
The invention relates to a polymer and more specifically to a modified high cis conjugated diene polymer.
2. Description of the Related Art
Conjugated diene polymer is widely used for resin modifying applications and various industrial goods. One of use is for manufacturing tires. Demand for low fuel consumption and attrition for the tires has increased with increasing environmental consciousness. For conforming the demand trend, the rolling resistance property, the wet traction property, the tensile strength property, etc. of mechanical characteristics of the conjugated diene polymer are very important.
The conjugated diene polymer having high content of cis-1,4 structure has good mechanical characteristics. There are many conventional methods for manufacturing the conjugated diene polymer having high content of the cis-1,4 structure. In those methods, catalysts formed by a combination of a metal compound, such as a Ni series, a Ti series, a Co series, a La series, etc. and an organic aluminum compound, are usually used.
The method for manufacturing the high cis conjugated diene polymer by using a lanthanide series metal has been increased to a mass production since the year of nineteen nineties. The conjugated diene polymer having high content of cis structure formed by a polymerization process using the lanthanide series metal compound as the catalyst composition has perfect linearity of the polymer chain and heavier molecular weight. Therefore, the conjugated diene polymer having high content of cis structure can be applied to applications of the tires, industrial goods. In addition, the conjugated diene polymer having high content of cis structure can be used for manufacturing goods having impact resistance.
There is no limit to methods for manufacturing a conventional catalyst composition of lanthanide series metal carboxylate. For example, the methods disclosed in U.S. Pat. No. 4,544,718, U.S. Pat. No. 4,520,177 or U.S. Pat. No. 5,220,045, etc may be used. Preferably, the lanthanide series metal compound may be manufactured by using materials of a lanthanide series metal oxide, an organic carboxylic acid and a huge amount of water. The lanthanide series metal oxide may use Nd2O3, Pr11O16, or Ce2O3, etc. The organic carboxylic acid is neodecanoic acid, lauric acid, tetradecanoic acid, or naphthenic acid, etc.
Currently, carbon black is added to the conjugated diene polymer to increase the strength of the tires. In recent years, due to the depletion of oil resource and the global warming issue, the industries have many methods by using silica as a reinforcing filler. In comparison with carbon black, silica is more difficult to be uniformly distributed in conjugated diene polymer. Therefore, the compatibility between silica and conjugated diene polymer needs to be further increased. According to one improvement method, when adding silica to the conjugated diene polymer during the manufacturing process of tires, a modifier is used to perform blending. However, since the blending uniformity largely affects the properties of the products, product quality may differ from batch to batch, and quality reproducibility is poor. Moreover, it is hard to make sure if the conjugated diene polymer is modified by the modifier, or the modifier only reacts with silica. Therefore, it is a prominent task for the industries to research a method for preparing the conjugated diene polymer with well dispersion property of silica.